MICROSTRUCTURAL AND PHYSICAL CHARACTERIZATION OF SOLID WASTES FROM CLAY BRICKS FOR REUSE WITH CEMENT
This study aims to evaluate the properties of different wastes obtained from four red ceramic brick industries in the northern region
of Santa Catarina, Brazil. The characterization of the clay brick waste (CBW) was performed using the XRD techniques, XRF,
FTIR, DTA and SEM. Techniques to determine the pozzolanic activity, particle size, B.E.T. surface area and specific mass were
used. The consumption of calcium hydroxide (CH) in the cementitious pastes with the CBWs was also measured. An application in
mortar is also analysed. The results indicated that the CH consumption was a function of the large surface area of the waste particles.
The CBW reactivity is favoured by firing temperature adequate (about 800 ºC), low presence of K2O and impurities and higher
kaolinite content. CBW-B showed the highest consumption of calcium hydroxide in the cement pastes tested (remaining 0.40%
CH). Morphological analysis showed that microcrystals of halloysite was smaller than those of kaolinite and have more elongated
profile. These differences provide the larger surface area observed for halloysite and this has an influence on the reactivity. The
reference paste presented CH content of 2.37%. The compressive strength of the mortar with CBW improved comparing to
reference, in 28 days (from 2.45 to 5.65 MPa), and in 90 days (from 5.72 to 10.39 MPa). The use of these wastes could reduce solid
waste discards in many regions. Besides reducing CO2 emissions and saving natural resources from the manufacture of cement.